I have read that other credit reporting companies are required by law to do this. But I don't know what the correct procedure is. It's not as simple as filing a dispute with these companies using their online dispute forms, because these don't allow you to attach information.
Do I mail a copy of the transunion resolution statement to the other companies intead?
Credit reporting agencies are required by law to keep your credit report as accurate as possible. If there are errors on your credit report you have to write to the credit bureau and request the information be corrected. If the error is with more than one credit bureau you will have to write to each of them directly to have them investigate the information. Each of the bureaus keep seperate records so a seperate investigation is required from each bureau. I suggest writing to the other bureaus (Experian and Equifax) and request they investigate and correct your information.
I have had the great displeasure of having to clean up all 3 of my credit reports manually. It can be a real hassle.
You will need to submit a separate dispute to each of the 3 major credit bureaus. Credit bureaus do not share information between them unless you have placed a fraud alert on your credit file. I would mail a letter to Equifax and Experian along with a copy of the Transunion resolution statement and supporting information, and request that they correct their records. They have 30 days to correct the item, and you should get an updated credit report in the mail when the investigation is complete. Make sure to keep copies of each correspondence as they can and do make mistakes in their investigations on occasion. By law, if you dispute an item on your report the credit bureau must verify the information with the reporting creditor. If they cannot verify the information, the item must be removed from your credit file.